Monarch butterfly populations are down
They are as much an autumn tradition as the changing of the leaves.
And many think the monarch butterflies are just as pretty.
Through most of September we watch a steady procession of monarchs moving south on those orange-and-black wings as delicate as tissue paper. This year’s show won’t be nearly as impressive as it has been in the past.
Some are wondering whether we had better enjoy what few we have … while we even have them.
Not many of America’s best-known butterflies will migrate south this fall. Some early estimates put the monarch butterfly population at more than 60 percent below last year.
Migrations are usually strongest in southern Kansas in mid-September.
“We had several bad things in a row,” said Chip Taylor, director of Monarch Watch, a conservation group based at the University of Kansas.
“First we had a late winter storm where they winter in Mexico. Then they had cold, rainy weather along much of their migration route. That put them into their breeding grounds late, and that’s never good.”
That’s especially bad news for a species with little margin for error.
Taylor said monarchs had great population numbers about 10 years ago. Now they’re being considered for federal threatened or endangered species listings.
Many scientists fear monarchs could be headed toward extinction in many areas of their current habitat range.
As well as concern for monarchs, Taylor and others worry that other pollinators, such as bees, are also in peril. That doesn’t bode well for humans because low pollinator numbers can cripple our food supply, with plants such as apples, almonds, pumpkins, oranges and avocados not growing because they aren’t pollinated.
The lack of pollinators can also affect the food that livestock eat.
Loss of habitat
Loss of habitat, the villain in most wildlife-related population problems, is to blame. In the case of monarchs, that means lack of milkweed plants on which adults lay eggs and on which monarch larvae feed.
Once a common wild plant across much of the nation, milkweed numbers have plummeted.
“We’ve lost well over 1.3 billion stems of milkweed in the upper Midwest,” Wayne Thogmartin, a U.S. Geological Survey ecologist, said of the multi-stemmed plants.
Taylor, from KU, estimated it would take up to 20 million acres of additional habitat to really help monarchs and other pollinators recover from recent losses. Agricultural herbicides and converting land into highways, houses and things such as golf courses are largely to blame for the decline.
Taylor said monarchs, like all insects, have been prone to population swings for centuries because of weather-related events. Most can quickly recover when conditions improve. The experts don’t see that happening for monarchs if things keep on as they are.
Monarchs coexisted well with agriculture until fairly recently. Taylor said that 15 years ago, farm fields were great places for insects to find needed plants, including milkweed that sprung up voluntarily among the crops.
Then, about 10 years ago, farmers began planting herbicide-resistant crops and butterfly populations began to crash.
Even once crops are growing, farmers can spray the fields with herbicide and kill all plants except the crop. The sprays are especially deadly to milkweed.
Reversing the decline
The plummeting monarch populations are drawing attention.
Ryan Drum, a U.S. Fish and Wildlife Service biologist who studies monarchs, said that about two years ago, the Obama administration issued a memorandum urging government agencies to work with private groups and businesses to reverse the decline. Taylor said about $7 million has been raised to do that, coming from government and private funds.
The Fish and Wildlife Service also is formally researching whether monarchs should be listed as threatened or endangered. Drum said the decision will be made by June 2019.
Most scientists familiar with the species say the monarchs can’t wait that long for added protection and habitat.
A study published in Scientific Reports in March said there is danger that within 20 years migrating monarch could become quasiextinct. Some populations in the southern U.S., where monarchs don’t migrate, are probably safe.
But it’s possible that the numbers of migrating monarchs could drop so low that the population couldn’t rebound, according to the article.
“Monarchs need other monarchs,” said Thogmartin, one of the authors of the study. “In Mexico, they gather in big clumps to stay warm and to protect them from the elements. They also need to be able to find other monarchs to mate.
“We don’t know what that (minimum) level is to still sustain a migratory population.”
Some models predict there could be a 50 percent or more chance that some widespread migrating populations could be basically extinct in about 20 years if trends don’t change. Other models, though, place the extinction probability substantially lower, in the teens.
Progress is being made, Taylor said, but there are still many hurdles in accumulating 20 million acres of habitat. That’s a lot of acreage and a lot of money, he said.
“But we’ve determined it’s time to get all hands on deck,” Taylor said. “We’re not going to save the monarch unless we engage about everybody.”
State and federal programs that could return thousands of miles of roadsides back to grasses and plants are expanding as money becomes available. Utility companies are being approached to use their rights-of-way for monarchs and other important pollinators.
Monarch Watch is making it as easy as possible for schools and the public to grow milkweed and other wildflowers on school grounds and in private yards.
Still, much depends on the most important partner – farmers – if the downturns are to be reversed.
“It’s a big education thing, and we’re trying to engage the farming community,” Taylor said. “I think we have their attention.
“The problem is we really need to move along at a much faster pace and much bigger scale.”
How to get involved
Lawrence-based Monarch Watch is marketing milkweed plants so the public can help with monarch butterfly restoration.
Chip Taylor, Monarch Watch director, said the group has helped place nearly 400,000 three-month-old plants the past several years. He said starting the plants from seeds is difficult for most people.
The plants are sold in 32-plant flats for $75, which includes shipping.
“If someone doesn’t need 32 plants, it’s a great way to get their neighbors involved,” Taylor said. “If we have many left, you can plant them now, but most are planted in May.”
Taylor said Monarch Watch has distributed free milkweed plants to 600 schools over the past two years at no cost, thanks to outside funding. Plants have also been given to a variety of habitat restoration projects along hiking trails and wildlife habitat areas.
For more information, go to www.monarchwatch.org or call 913-864-4441.